2121020021969 has 2 divisors, whose sum is σ = 2121020021970. Its totient is φ = 2121020021968.

The previous prime is 2121020021947. The next prime is 2121020021977. The reversal of 2121020021969 is 9691200201212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1652600236225 + 468419785744 = 1285535^2 + 684412^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121020021969 - 2⁸ = 2121020021713 is a prime.

It is a super-3 number, since 3×2121020021969³ (a number of 38 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (2121020041969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060510010984 + 1060510010985.

It is an arithmetic number, because the mean of its divisors is an integer number (1060510010985).

Almost surely, 2^{2121020021969} is an apocalyptic number.

It is an amenable number.

2121020021969 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121020021969 is an equidigital number, since it uses as much as digits as its factorization.

2121020021969 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 35.

The spelling of 2121020021969 in words is "two trillion, one hundred twenty-one billion, twenty million, twenty-one thousand, nine hundred sixty-nine".